Embodiments of the present invention relate to mixed-domain oscilloscopes, and more particularly, to instruments, systems and methods for making measurements on a mixed-domain oscilloscope using an internal chirp generator, an output channel, an RF input channel, and time alignment logic.
Unlike traditional swept or stepped spectrum analyzers, a mixed-domain oscilloscope (MDO) uses fixed local oscillators (LOs) to block convert wide swaths of bandwidth as opposed to sweeping or stepping an LO through an equivalent wide bandwidth. Traditional spectrum analyzers provide a tracking generator, which uses the swept or stepped LO to produce a signal that tracks with the sweep of the analyzer. The swept signal is fed to a network or device under test and the resulting signal is analyzed using the spectrum analyzer. This is known in the industry as a “poor man's network analyzer” because while this technique provides a useful method for determining scalar measurements, it is incapable of providing vector measurements as provided by conventional network analyzers.
There is a trend in the test and measurement field to provide multiple functions that were traditionally provided in separate instruments, within a single test and measurement instrument in a time-correlated fashion. One such instrument is the MDO, which includes digital channels, analog channels, and an RF input channel all within a single instrument. Presently, MDOs do not offer a “poor man's network analyzer” capability because the typical approach uses the swept or stepped LO approach, which differs from the traditional way in which data is acquired and processed on an MDO.
It would be desirable to provide an MDO with an internal chirp generator and the capability of transmitting a chirp signal. Moreover, it would be desirable to provide time alignment logic for time aligning the chirp signal with an acquisition so that a user can obtain and analyze measurements such as scalar s parameters. Embodiments of the invention address these and other limitations in the prior art.
The foregoing and other features and advantages of the inventive concepts will become more readily apparent from the following detailed description of the example embodiments, which proceeds with reference to the accompanying drawings.